Whole genome association analysis suggest an influence of inbreeding on bull sperm morphometry

JESÚS DORADO; DEMYDA-PEYRÁS, SEBASTIÁN; MARINA SOLÉ; ESTER TERÁN; FLORENCIA AZCONA; PABLO JUAN ROSS

New Orleans

Conferencia; 45th Annual Conference of the IETS; 2019

International Embryo Technologies Society

Inbreeding depression, the genetic condition caused by mating related individuals, is particularly important in several cattle breeds with limited effective populations. This condition is often associated with decreases in performance, including fertility. Furthermore, sperm head morphometry was associated with fertility in several species. To our knowledge, the influence of inbreeding on sperm morphometry has not been widely reported in cattle. In this study, a Sperm Class Analyzer (SCA?, Microptic, Spain) was used to characterize seven sperm morphometry parameters in 59 Retinta bulls, including sperm head length (Le), width (Wi), perimeter (Pe), ellipsicity (El), elongation (En), regularity (Re) and rugosity (Ru). Two replicates of at least 100 sperm heads, from two frozen semen samples, were assessed per individual (n=200 sperm/bull). Additionally, all individuals were genotyped with the Axiom Bos1 high density SNP Array (Affymetrix, USA). The molecular-based inbreeding factor (FROH; mean 12.5%, range 1.75 to 33.0) had very low correlations with all sperm morphometry parameters. On average, sperm heads from bulls with higher FROH had a smaller area, but variability was high. Correlations between inbreeding and sperm shape were low and negative, being Le (r=-0.1449, P